When redesigning the Aeffect stem, Race Face set out to capture the reliability and light weight characteristics that we found in the original model, with added strength for an all mountain and enduro riding, and shorter lengths that cater towards modern bike geometry. The Race Face Aeffect R 35mm stem offers just that, plus the ability to run an extra stiff and beefy 35mm handlebar. Machined out of forged 6061 aluminum, the Aeffect R is lightweight without sacrificing strength, and reinforces your cockpit with a burlier bar than smaller 31. 8 stems, which won't provide you with the same stiffness and security on the rougher downhills.